Experimental evidence of the double-porosity effects in geomaterials

Tien Dung Tran Ngoc (1, 2) , Jolanta Lewandowska (3) , Henri Bertin (4, 5)

1 INRS - Institut National de la Recherche Scientifique [Québec]
2 Faculty of Chemical Engineering [Vietnam National University, HCM]
3 PMMD - Physique et Mécanique des Milieux Divisés
4 I2M - Institut de Mécanique et d'Ingénierie de Bordeaux
5 TREFLE - Transferts, écoulements, fluides, énergétique

Double-porosity is an important characteristic of microstructure in a large range of geomaterials. It designs porous media with connected fissures/fractures or aggregated soils. The origin of double-porosity can be natural or/and it can result from mechanical, chemical or biological damage. The presence of double-porosity can significantly affect the behaviour of geomaterials. In this paper we provide an experimental evidence of the double-porosity effects by performing laboratory experiments. Series of tracer dispersion experiments (in saturated and unsaturated steady-state water flow conditions) in a physical model of double-porosity geomaterial were carried out. For the comparative purposes , experiments of the same type were also performed in a single-porosity model medium. The results clearly showed that the double-porosity microstructure leads to the non-Fickian behaviour of the tracer (early breakthrough and long tail) in both saturated and unsaturated cases.

Mots clés: double-porosity; physical model; unsaturated/saturated con- ditions; tracer dispersion; non-Fickian behaviour

Domaines: Mécanique [physics.med-ph]

Tien Dung Tran Ngoc, Jolanta Lewandowska, Henri Bertin. Experimental evidence of the double-porosity effects in geomaterials. Acta Geophysica, 2014, 62 (3), pp.642-655. ⟨10.2478/s11600-013-0198-x⟩. ⟨hal-02092974⟩